Tiscali has kicked off legal proceedings against BT, after the telecoms giant sent letters to the Italian-owned ISP’s customers earlier this month.

The personalised marketing letter, a scan of which can be viewed here, referenced a story written in January this year by The Register that first highlighted that the UK arm of Tiscali could be up for sale.

BT had hoped to convince customers to shift over to its own broadband offering.

Tiscali confirmed yesterday that legal proceedings had been issued against BT for “defamation and malicious falsehood”.

It added that “BT has disputed the claim. The next stage is for us to file a further court document and we will then learn the terms on which BT intends to defend the claim, if at all.”

A BT spokesman dismissed Tiscali’s allegations. “Following media reports suggesting that Tiscali was up for sale we recently approached a number of Tiscali customers, and pointed out the benefits of our service,” he said. “We believe this is a legitimate and reasonable business practice - comparative marketing is an important aspect of a competitive market.”

Italian-bought Tiscali put itself up for sale in February. Several companies, including Sky and Carphone Warehouse, are thought to have put in bids for the UK business, but no buyers have been announced. ®